Centrifugal treating machine



Mmh 27, 1934. A, H ADAMS 1,952,574

CENTRIFUGAL TREATING MACHINE Original Filed April 13. 1928 2Sheets-Sheet 1 #M g l ATTORNEY March 27, 1934. A, H, ADAMS 1,952,574

CENTRIFUGAL TREATING MACHINE original Filed April 13, 192s 2sheets-sheet 2 Patented Mar. 27, 1934 PATENT OFFICE CENTRIFUGAL TREATING MACHINE Arthur l-I. Adams, New York, N. Y.

Original application April 13, 1928, Serial No.

269,851. Divided and this application November 17, 1930. Serial No.496,358

8 Claims.

This invention relates to Icentrifugal treating machines, and inparticular to extractors.

In machines of the above-noted character various arrangements have beenproposed for overcoming the deleterious effects due to centrifugalunbalance. For example, in one type of extractor, i. e., the overdriventype, the extractor. basket is attached to the lower end of a relativelylong vertical shaft which, with the supports for the 10 upper bearingand drive, interfere materially with the charging of the basket withmaterials and also makes this construction costly. In this constructiongravity tends to bring the shaft to a true vertical and the basket isusuallyA rigidly attached to the shaft, or is otherwise so mounted thata displacement of the shaft from the vertical will tip the basket. When,therefore, the basket is unbalanced by the load and the driving torsionis applied, the tendency of the mass to revolve about the center ofgravity-causes the shaft and basket to swing out of the centralposition,

tipping the basket. This tipping gives rise to a the shaft will onlyresult in what may be calleda normal precession of the shaft axis and ofthe basket. If, however, the basket is unbalanced, i. e., if its centerof mass does not coincide with the geometrical center 'of the shaftwhich is the usual case. this precessional motion of thef'shaft axiswill be irregular and will vary Within wide limits, especially while thebasket is coming up to speed. This irregular precessional motion appearsin the'form of undesirable vibration of the basket, which may cause thebasket to strike the guard or curb and it may even be so violent as tobe dangerous toattendants.

In accordance with the present invention undesired vibration is avoidedby allowing the basket automatically and speedily to assume, withoutrestraint,'a position n which it may rotate freely about the verticalaxis through its center of mass. Further, all precessional motion ismade impossible by confining the movement of each particle of therotating mass to a plane normal to thatner of coupling a rotatingelement with a driving device in accordance with the disclosure of myThe principal object of the invention is to` provide a centrifugaltreating machine preferably vof the underdriven type in which theeffects of unbalance and of incorrect starting position, are reduced toa minimum. 60

Another object is to provide a centrifugal treating machine wherein therotating element is laterally unrestrained and therefore freeautomatically to assume a position of free rotation about an axisthrough its center of mass, and wherein it is confined to motion in aplane and not subject to precessional disturbances.

Another object is to provide a centrifugal treating machine having meansfor applying substantially pure torque to the rotating element.

A further object resides in a basket for a centrifugal machine which ismounted for substantially unrestrained motion in a horizontal plane.

A feature of the invention pertains to the manshaft, whereby saidelement is capable of unrestrained movement in a plane at right anglesto the said shaft.

Another feature resides in the combination of a rotating platform withan Aextractor basket mounted on, and adapted to rotate at the 4sameangular velocity with, said platform and also capable of simultaneouslateral movement on said platform with a minimum of friction.

A further feature resides in a modified form of universal coupling fortransmitting substantially pure torque to an extractor basket.

A further feature ofthe invention relates to novel means forcentrifugally balancing a rotating element.

A still further feature is concerned with covercontrolled means forcentering an extractor basket with respect to a ldriving shaft.

Other features and advantages of theinvention which have not beenspecifically enumerated will become apparent after a consideration ofthe following detailed description and the" appended claims.

While it has been chosen to'disclosev the inventive idea in connectionwith a centrifugal machine of specific construction, suitable for use asa laundry extractor, it is understood that this is merely for thepurpose of description in order that a clear understanding maybeattained of one particular mode of practising the invention, andapplications to other types of machines are within the compass of theinvention.

Referring to the drawings, which show my co-pending application, SerialNo. 269,851, filed April 13, 1928, of which this application is adivision.

Fig. 1 shows a view in sectional elevation of a machine embodying thevarious features of the invention;

Fig. 2 shows a plan view in section of apart of the machine of Fig. 1,the section being taken along line 2 2 of Fig. 1;

Fig. 3 is a detail view of one of the basket supporting members;

Figs. 4 and 5 are detail views of one of the pinslot universal couplingvmembers;

Fig. 6 shows another embodiment of the invention employing analternative form of frictional basket support;

Fig. 7 is a detail plan view of the anti-frictional basket supportingmember shown in the embodiment of Fig. 6;

Fig. 8 is an enlarged view of a section of the member shown in Fig. 7;

Fig. 9 is a detailed view illustrating rthe relation between the drivingplatform and the frictionless support of Fig. 6 and showing particularlya means to restrain the basket carrier 5 against vertical movement whileallowing ample freedom in one plane.

The machine in connection with which it has been chosen to illustratethe invention is generlcally known as a centrifugal extractor andcomprises a curb or outer casing l (Fig. l) having a top opening 2adapted to be closed when the machine is in operation by a suitablecover preferably divided in half and hinged at opposite sides of thecurb as represented by the numerals 3,'for purposes hereinafterdescribed. The lower portion of the curb is in the form of a hollowpedestal and serves as a housing for the driving gears, clutch mechanismand other portions of the machine. The opening 2 in the curb ispreferably sufficiently large to permit the extractor basket 4 to beraised and lowered on o the carrier 5. As shown in Fig. 1. the basket!has a reentrant central portion of the same gen ral shape as, andadapted to t over, the carrier 5 which is antifrictionally mounted uponthe rotating-platform 'rotating carrier and basket for purposeshereinafter described. The reentrant portion of the basket 4 isunperforated While the side walls are copiously perforated for theejection of liquid or other extract thrown vfrom the materials undertreatment. As indicated by the numeral 7 the basket is provided at itscenter with a hook or its equivalent, by means of which t-he basket may'Ihis feature of having the basket removable is` highly desirable inmachines that are employed las laundry driers, since it permits thebasket to be transported on overhead conveyorsor the like and theattendant may more evenly distribute the load in the basket while it issuspended by the hook 7 outside the curb at the appropriate loadingstation. Any form of. coupling may be provided between the carrier 5 andthe basket 4. For example, the raised central portion of the carrier 5may be provided with a square hole which registers with a correspondingsquare projection 8 on thecenter of the basket.

anti--V structure for the retention of a layer of oil or other lubricantand also acts as a ring for preventing the extracted liquid from gainingaccess to the platform proper. Platform 6 is secured to shaft 9 forrotation therewith, said shaft being provided at its lower extremitywith a suitable non-frictional step-bearing represented schematically bythe numeral 10. It will be understood that platform 6 must preferablyspin in a quite truly horizontal plane. be desirable to provideadjustable connections between shaft 9 and platform 6, whereby the saidplatform may be permanently and accurately fastened to enable it torotate in a true horizontal plane.

The numeral 11 represents the motor driving shaft which transmits itspower to shaft 9 through helical gears 12 and 13. Suitably supported onthe interior of the hollow pedestal portion 14 of the ,curb is a box 15which encloses a braking mechanism for shaft 9. This brake comprisesalternate circular discs 16 which are splined to shaft 9, and discs 17which loosely engage said shaft. Between these sets of discs 16 and 17are thin sheets of friction material 17. The pressure between the discsand consequently their friction may be regulated by suitable adjustingmeans schematically represented by the compression spring 18 and theadjusting nut 19.

As shown clearly in Fig. 1, the entire weight of the basket 4 andcarrier 5 is anti-frictionally supported on platform 6, preferably atdiametrically opposite points on ball-bearing casters 27, or the like,one of which is shown in detail in Fig. 3. Each caster (Fig. 3)comprises a spherical bearing member 28 which rotates in the housing 29and is backed by balls 30 which are enclosed by the cover 31 throughwhich the member 28 protrudes. The leg 32 which is preferably formedintegral with the housing 29 is fastened by appropriate means, as byrivets, to the bottom of the carrier 5. Thus, carrier 5 and the chargedbasket 4 being anti-frictionally supported are free to move in anydirection on the platform 6. For the purpose of transmitting the rotarymotion of shaft 9 to the basket 4 without interfering with the freetranslational movement of said basket ori the platform 6, that is-tosay, for applying a substantially pure torque to the basket, there isprovided a novely form of an extensible shaft having universalconnections atv opposite ends with the platform 6 and the carrier 5 sothat said carrier 5 is free to move relative to the platform 4 at thesame time that itis being rotated. For this purpose the platform 6 iscoupled to the carrier 5 by universal coupling members, one of which isshown in detail in Figs. 4 and 5. This coupling member comreadily beraised and lowered on to the carrier 5.

prisesv a hollow cylindrical member 33 having two slots 34 at oppositesides thereof, which are adapted to receive pins35 formed integrallywith the spherical end 36 of the member 37. The slots 34 in the member33 are sumciently long to permit the member 37 tovmove freely'in avertical direction. Due to the length of the slots 34 which engagerthepins 36 as Well as the ball and socket arrangement between the end 36and member 33,

For this purpose it may f the member 37 is capable, during rotation, ofi universal movement Ywith respect to the member 33. lA similaruniversal coupling is provided be both ends of the shaft 37, when theplatform 6 is rotated a corresponding angular velocity is transmitted tothe carrier 5 and the loaded basket 4 through the shaft 37, which isfree to assume substantially any angular position with relation to thedriving shaft 9. In other words, pure torque may be transmitted from theshaft 9 to the carrier 5 regardless of the position of the said carrierand basket on the platform 6. It is obvious therefore that should theload in the basket 4 be unevenly distributed, whereby the center of massof the rotating system as a whole is displaced laterally with respect tothe center of shaft 9, because of the anti-'frictional mounting of thecarrier and basket and because of the universal coupling between theplatform 6 and the carrier 5 the drum is enabled to start rotation atonce about some vertical axis without any substantial restraint, and theposition of this vertical axis is determined by the location of thecenter of the mass at the time of applying torque. This results from thefact that the member 37, while it is capable of transmitting torque tothe loaded basket and of rotationally accelerating the mass is incapableof exerting any but an extremely small lateral or translational force onthe mass. Thus, the charged basket is free, within certain wide limits,to spin about any point on the platform 6 when it is being rotated bythe member 37. In this connection it will be noted that the entireweight of the carrier and loaded basket is borne entirely by theanti-friction members 27 and not by the universal coupling members.

For the purpose of automatically reducing the eccentricity between thecenter of mass of the system comprising the rotating basket and carrier,and the geometrical center of said system, the carrier 5 is providedwith a. novel form of centrifugal balancing arrangement comprising anannular pipe or tube 40 fastened to the outer rim of the carrier 5 inany suitable manner. The tube 40 contains a `quantity of fiowablematerial preferably of a heavy character such as mercury, mercuryamalgam, steel balls, or the like.` Consequently, if the center of massof the charged basket is eccentric, the flow of material in the tube 40,due to centrifugal force, will tendto move it the greatest possibledistance from the center of mass of the rotating system. For example, ifthe basket 4 shown in Fig. 1, is so loaded that the center of mass isdisplaced to the right,

then it will start rotating about this center of mass and the portion ofthe basket and of pipe 40 that was initially `at the left, will be at agreater distance from the center of rotation than any other side.Consequently, the material in tube 40 will tend to accumulate in thisinitially left-hand portion thereof, which, in effect, causes a gradualdisplacement of the center of mass of the entire system toward the leftuntil the eccentricity is a minimum. This, of course, does not shift,relative to the earth, the position of the center that the mass spinsabout. The quantity of material in the tube 40 and the size of said tubemay be so designed that the maximum displacement of the center of massof the rotating system as found in practice may be very nearlycounteroalanced. For the purpose of causing the material in tube 40 tomove steadily and not too violently toward the unbalanced side of therotating system, that is, to prevent surges in the flow of material dueto acceleration ofthe basket and carrier and to prevent sudden changesin the center of mass of the system, the interior of the tube 40, asindicated by the numeral 41, is provided at various points with baflieplates, gratings, perforated plates, or the like, for the purpose ofdampening out such surges of the column of flowing material.

A typical operation of the machine is" as follows:

The basket 4 having been previously removed by suitable conveyingmechanism, preferably of the overhead trolley type, is charged as evenlyas possible. For this purpose special balancing means may be provided ifdesired, or it may be loaded or readjusted while suspended in order thatthe attendant may most accurately distribute the material uniformlyabout the geometric center of the basket. When the basket has been thuscharged it is conveyed from the charging location to the extractor andlowered through the opening 2, and rotated by hand until the pro jection6 of the basket registers with the correspending hole in the carrier 5.The attendant thereupon closes both halves 42 and 43 of the curb cover.In this connection it will be noted thatevery time the covers are openedthe basket is mechanically centered within the curb. This '100 iseffected through the intermediary of the centering fingers 44, whichmove in unison with the respective cover members 42 and 43. When thecovers are closed fingers 44 assume the positions shown in full lines inFig. .1. As the covers are raised the ngers move through correspondingopenings 45 in the side of the curb until said fingers engage the sidesof the basket 4, as represented by the dotted line positions. Suitablestops 46 are provided to limit the inward movement of the fingers 44 inwhich position the basket is accurately centered on the platform 6.While` only two centering fingers at diametrically opposite points areshown, it will be understood that two or more may be provided for eachhalf of the cover, the essential thing being that the raising andlowering of the cover causes the basket to be pushed to the center ofplatform 6. If an electric motor is used, the switch for turning on themotor at the same time energizes the solenoid 26 whereby the frame '22is drawn out'of engagement with the clutch discs 17 which are thereuponfree to rotate with the shaft 9 which in turn rotates the platform 6.When shaft 9 rotates a torque is transmitted through the member 37 tothe basket and carrier which are therefore constrained to rotate at thesame angular velocity as the .shaft 9. If the basket is accuratelybalanced initially, and since it started geometrically centered over thecenter of shaft 9, it is obvious that the center of the mass will besubstantially in line with the axis of the shaft 9. Consequently whentorque is transmitted through the member 37 the platform 5 with thebasket 4 will find its natural center of rotation to be sub- 135stantially in line with shaft 9 and will rotate resting on the platform6 without any motion relative to said platform. The material in the tube40 will have been symmetrically distributed in the tube by gravity andwill not shift.

Obviously center over'platform 6: moreover, if the basket il;

translatory inertial resistance increases,v relative to rotational,permitting higher friction to be overcome using the same or less torque.This will have the effect of causing every point of the basket andcarrier and the anti-friction supporting members 27 (Fig. 3), inparticular, to deg scribe circles over the surface of platform 6. Thesecircles will al1 have the same radius and this radius will be equal tothe displacement of the center'of mass from the center of the ma chine.The action will be much like that of rubbing the two hands together witha simultaneous circular movement.

Due to the balancing effect of the material in tube 40, the eccentricityof the center of mass in the basket is progressively decreased by thematerial in said tube tending to move in a direction opposite to thedisplacement of the' center of 'mass Since the basket and carrier formaclosed system incapable of receiving any translational force, this willnot, as vmight at first be supposed, bring the center of mass anynear'er the axis of shaft 9, but merely reduces the eccentricity of thebasket.

Of course the optimum counterbalancing condition would be attained ifthe material in'tube 40 'could entirely counterbalance the unbalancedload and if the center of mass could thus be brought absolutely tocoincide with the center of the basket.

Further, it is desirable that the nal center of mass (and of rotation)of the basket, even though toone side o f the geometric center of thebasket, should be brought to the center of the machine. For in thiscondition the handrubbing movement'of the support 5 and of the basketrelative to platform 6 will cease entirely.

While the center of mass, because of the lack of all constraint, willnot be driven farther from the centerof the machine by centrifugalforce, there are only very weak forces (such as the' greater airpressureon the basket at any side where it runs nearer the curb) toimpel it to the machine center. A slight tilt of platform 6 might causegravity to overcome this air force. Hence,

it'has been found advisable to supply a set of light centering springs47, 48, weakly tending to locate carrier 5 with its center over the axisof shaft 9.

These should be relatively weak in order not to provide suiiicientlateral constraint to the self-centering action of the basket to causeit to develop appreciable centrifugal force. It is clear that, werethese springs strong, they would hold the geometric center of the basketon the machine center, regardless of the position of the center of mass.The universal jointed coupling member 37 would still force the basket tospin, but the center of mass of the basket would be forced to revolve(relative to the earth) about the center of the machine, instead ofremaining stationary (relative to the earth) l as through inertia ittends to do, and as it is the great advantage of this invention topermit it to do. A set of lightsprings, especially if connected, asshown on a slant,A will not give constraint enough to compel the centerof mass to revolve and yet will slowly draw basket and carrier 5 as nearas possible to their centering on the :machine center. When the centerof mass of the basket'is over the machine center these springs are asnearly satisfied as possible and no further relative movement will occurbetween carrier tandsupport 6.

is centrally weighted as suggested (page 2), s After the extraction iscompleted, the motive power is turned o ff causing a deenergization ofthe solenoid 26 and a retraction of the frame 22 into engagement withthe clutch discs 17. The frame 22 thereupon grips the next set of projections 21, for example, and positively prevents further rotation ofthe driving discs 17. The

shaft 9 is therefore subjected to a continuous braking action.

While a specific form` of extensible universal coupling is providedbetween the carrier 5 and the platform 6, it will be obvious that anyother form may be employed. For example, instead of relying upon theslots 34 for permitting the lateral movement of the basket, the shaft3'? may be of the telescoping kind and well known forms of universalcouplings may be provided between the two ends of the telescoping shaftand the support 5 and platform 6 respectively.

Referring to Fig. 6, there is shown another modification of theinvention in which the basket -4 instead of being mounted onball-bearing casters is mounted on a ball bearing thrust ring comprisinga circular sheet of metal 49 (Fig. 7) having a series of balls 50,rotatably mounted in corresponding perforations in the plate 49. Anywell known manner of mounting the balls in the plate, to enable theballs to freely move without dislodgment, may be employed. For eX-ample, the surfaces of the plate may be punched, as indicated by thenumeral 51, to retain the balls therein. As shown in Fig. 6, the carrier5 is coupled to the rotating platform 6 by an extensible universalcoupling member 37 so that when member 37 is moved angularly withrespect to the driving shaft 9, the plate 49 also moves to correspond,but to just half the extent. This would be the natural movement of plate49 if carried by the perfect rolling of balls 48. This coupling of plate49 to member 37 at onehalf the height of the latter serves to counteractany tendency of the latter to slip or creep.

' For the purpose of limiting any possible vertical displacement of thebasket 4, the same is provided with downwardly projecting pins 53 (Fig.9) which pass through relatively large openings 54' and 55 in themembers 49 and 6 respectively. The pins 53 carry at their lower endsmembers 56 which are larger than the openings 55. so that the verticalmovement of carrier `5 is limited. Since basket 4 and platform 6 rotatewith the same velocity, this limiting arrangement does not interferewith the free movement of the basket on the platform. It will beunderstood that the platform 6 has oil for reducing the friction betweenthe member`49 and the said platform. The remaining parts of the machineshown in Fig. 6 may be similar to those disclosed in connection withFig. 1 and it is believed 'that the operation of this embodiment of themachine will be understood from the description given hereinabove. Inthis connection it may be noted that the embodiment treating machinehaving a basket or container* which is substantially free to revolveabout its center of mass without undesirable vibration.

What I claim is:

1. In a centrifugal treating machine, a rotating platform, a drumcarrier anti-:frictional means mounted on said carrier to support saidcarrier on said platform, means constraining said carrier to move at thesame angular velocity as said platform without otherwise restraining thefreedom of movement of said carrier on said platform.

2. In a centrifugal treating machine, a vertical driving shaft, aplatform, a basket antifrictionally mounted on said platform, and acoupling member universally -connected at opposite ends to said shaftand said basket respectively.

3. In a centrifugal treating machine, a basket substantially freetranslationally in one plane only, and means to apply to said basket .asubstantially pure turning movement in said plane.

4. Ina centrifugal treating machine, a horizontal table, a rotatingvertical shaft, a basket, anti-friction bearings supporting said basketand permitting free movement of said basket over said table in anydirection, and means including said shaft for imparting to said basketsolely a turning movement.

5. In a centrifugal treating machine, a basket mounted for substantiallyunrestrained movement in a plane, means for applying substantially puretorque to said'basket whereby it rotates around its centerl of mass, andmeans to autodriving shaft for driving said platform, a second shaft forrotating said basket with said platform,

said second-named shaft comprising an extensible universal couplingbetween said basket andL said platform.

7. In a centrifugal extractor of the underdriven type, a platform, abasket, anti-frictional means supporting said basket on said platform, adriving shaft for driving said platform, a second shaft for rotatingsaid basket with said platform, said second-named shaft comprising an'extensible universal coupling between said basket and said platform,and symmetrically arranged resilient means connecting said platform andbasket, whereby any tendency of said basket for precessional movement issubstantially inhibited.

8. In a centrifugal treating machine, a rotor that may be unbalancedlyloaded with material, means substantially to constrain said rotor tomovements in a gravitationally equipotential plane, antifrictional meansto minimize all frictional restraint on said rotor in that plane, meansto apply to said rotor a strong purely rotational force substantiallyabout an axis normal to that plane, and a very light centering device toprevent said rotor from slowly wandering in that plane.

ARTHUR H. ADAMS.

